TY  - JOUR
A1  - Schael, S.
A1  - Atanasyan, A.
A1  - Berdugo, J.
A1  - Bretz, T.
A1  - Czupalla, Markus
A1  - Dachwald, Bernd
A1  - Doetinchem, P. von
A1  - Duranti, M.
A1  - Gast, H.
A1  - Karpinski, W.
A1  - Kirn, T.
A1  - Lübelsmeyer, K.
A1  - Maña, C.
A1  - Marrocchesi, P.S.
A1  - Mertsch, P.
A1  - Moskalenko, I.V.
A1  - Schervan, T.
A1  - Schluse, M.
A1  - Schröder, K.-U.
A1  - Schultz von Dratzig, A.
A1  - Senatore, C.
A1  - Spies, L.
A1  - Wakely, S.P.
A1  - Wlochal, M.
A1  - Uglietti, D.
A1  - Zimmermann, J.
T1  - AMS-100: The next generation magnetic spectrometer in space – An international science platform for physics and astrophysics at Lagrange point 2
JF  - Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Y1  - 2019
U6  - https://doi.org/10.1016/j.nima.2019.162561
SN  - 0168-9002
VL  - 944
IS  - 162561
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Saretzki, Charlotte
A1  - Bergmann, Ole
A1  - Dahmann, Peter
A1  - Janser, Frank
A1  - Keimer, Jona
A1  - Machado, Patricia
A1  - Morrison, Audry
A1  - Page, Henry
A1  - Pluta, Emil
A1  - Stübing, Felix
A1  - Küpper, Thomas
T1  - Are small airplanes safe with regards to COVID-19 transmission?
JF  - Journal of Travel Medicine
Y1  - 2021
U6  - https://doi.org/10.1093/jtm/taab105
SN  - 1708-8305
VL  - 28
IS  - 7
PB  - Oxford University Press
CY  - Oxford
ER  - 
TY  - CHAP
A1  - Roosen, Petra
A1  - Feyerl, Günter
T1  - Gender-specific perception and utilization of personal use vehicles
T2  - FISITA World Automotive Congress 2014 : Maastricht, The Netherlands, 2 - 6 June / [organised by the International Federation of Automotive Engineering Societies (FISITA) ...]. Bd. 1
Y1  - 2015
SN  - 978-1-5108-0209-4
SP  - 418
EP  - 425
PB  - Curran
CY  - Red Hook, NY
ER  - 
TY  - JOUR
A1  - Robinson, A. E.
A1  - Rönna, Uwe
A1  - Funke, Harald
T1  - Testing of a 10 kW diffusive micro-mix combustor for hydrogen-fuelled micro-scale gas turbines
JF  - International Workshop on Micro and Nanotechnology for Power Generation and Energy Conversion Applications <7, 2007, Freiburg, Breisgau>  ; PowerMEMS ; 7
Y1  - 2007
SP  - 225
EP  - 228
ER  - 
TY  - JOUR
A1  - Robinson, A. E.
A1  - Funke, Harald
A1  - Wagemakers, R.
A1  - Grossen, J.
A1  - Bosschaerts, W.
A1  - Hendrick, P.
T1  - Numerical and Experimental Investigation of a Micromix Combustor for a Hydrogen Fuelled μ-Scale Gas Turbine
JF  - Proceedings of the ASME Turbo Expo 2009 : : presented at the 2009 ASME Turbo Expo, June 8 - 12, 2009, Orlando, Florida, USA / sponsored by the International Gas Turbine Institute
Y1  - 2009
SN  - 9780791848869
N1  - GT2009-60061
SP  - 253
EP  - 262
PB  - ASME
CY  - New York, NY
ER  - 
TY  - JOUR
A1  - Robinson, A. E.
A1  - Funke, Harald
A1  - Hendrick, P.
A1  - Recker, E.
A1  - Peirs, J.
T1  - Development of a hydrogen fuelled 1 kW ultra micro gas turbine with special respect to designing, testing and mapping of the µ-scale combustor
JF  - IEEE International Conference on Sustainable Energy Technologies, 2008 : ICSET 2008 ; Singapore, 24 - 27 Nov. 2008.
Y1  - 2008
SN  - 978-1-4244-1887-9
SP  - 656
EP  - 660
PB  - IEEE
CY  - Piscataway, NJ
ER  - 
TY  - JOUR
A1  - Robinson, A. E.
A1  - Funke, Harald
A1  - Hendrick, P.
T1  - Design and Testing of a Micromix Combustor With Recuperative Wall Cooling for a Hydrogen Fueled µ-Scale Gas Turbine
JF  - Journal of engineering for gas turbines and power
Y1  - 2011
SN  - 1528-8919
VL  - 133
IS  - 8
PB  - ASME
CY  - New York
ER  - 
TY  - CHAP
A1  - Rings, René
A1  - Ludowicy, Jonas
A1  - Finger, Felix
A1  - Braun, Carsten
A1  - Bil, Cees
T1  - Sensitivity Analysis of General Aviation Aircraft with Parallel Hybrid-Electric Propulsion Systems
T2  - Asia Pacific International Symposium on Aerospace Technology. APISAT 2019
Y1  - 2019
ER  - 
TY  - GEN
A1  - Reiswich, Martin
A1  - Brandt, Hannes
A1  - Czupalla, Markus
T1  - Passive thermal control by integration of phase change material into additively manufactured structures
T2  - E2. 47th Student conference
N2  - Optical Instruments require an extremely stable thermal surrounding to prevent loss of data quality by misalignments of the instrument components resulting from material deformation due to temperature f luctuations (e.g. from solar intrusion). Phase Change Material (PCM) can be applied as a thermal damper to achieve a more uniform temperature distribution. The challenge of this method is, among others, the integration of PCM into affected areas. If correctly designed, incoming heat is latently absorbed during phase change of the PCM, i.e. the temperature of a structure remains almost constant. In a cold phase, the heat during phase change is released again latently until the PCM returns to its original state of aggregation. Thus, the structure is thermally stabilized. At FH Aachen– University of Applied Sciences research is conducted to apply PCM directly into the structures of affected components (baffles, optical benches, electronic boxes, etc.). Through the application of Additive Manufacturing, the necessary voids are directly printed into these structures and filled later with PCM. Additive Manufacturing enables complex structures that would not have been possible with conservative manufacturing methods. A corresponding Breadboard was developed and manufactured by Selective Laser Melting (SLM). The current state of research includes the handling and analysis of the Breadboard, tests and a correlation of the thermal model. The results have shown analytically and practically that it is possible to use PCM as an integral part of the structure as a thermal damper. The results serve as a basis for the further development of the technology, which should maximize performance and enable the integration of PCM into much more complex structures.
Y1  - 2019
N1  - 70th International Astronautical Congress, 21. - 25. Oktober 2019, Washington D.C., United States
ER  - 
TY  - CHAP
A1  - Reimer, Lars
A1  - Wellmer, Georg
A1  - Braun, Carsten
A1  - Ballmann, Josef
T1  - Computational methods for aero-structural analysis and optimisation of aircrafts based on reduced-order structural models
T2  - MEGADESIGN and MegaOpt - German initiatives for aerodynamic simulation and optimization in aircraft design. Results of the closing symposium of the MEGADESIGN and MegaOpt projects, Braunschweig, Germany, 23 - 24 May, 2007 / Norbert Kroll ... (Eds.) Notes on numerical fluid mechanics and multidisciplinary design. Vol. 107
N2  - In this part of the MEGADESIGN project, aeroelastic effects are introduced into the aerodynamic analysis of aircrafts by coupling DLR’s flow solvers TAU and FLOWer to a Timoshenko-beam solver. The emerging aeroelastic solvers and a method for the automatic identification of Timoshenko-beam models for wing-box structures were integrated into a simulation environment enabling the combined optimisation of aerodynamic wing shape and structure.
Y1  - 2009
SN  - 978-3-642-04092-4
SP  - 135
EP  - 150
PB  - Springer
CY  - Berlin
ER  - 
TY  - CHAP
A1  - Reimer, Lars
A1  - Braun, Carsten
A1  - Wellmer, Georg
A1  - Behr, Marek
A1  - Ballmann, Josef
T1  - Development of a modular method for computational aero-structural analysis of aircraft
T2  - Summary of flow modulation and fluid-structure interaction findings. Results of the Collaborative Research Center SFB 401 at the RWTH Aachen University, Aachen, Germany, 1997-2008 / ed.: Wolfgang Schröder. Notes on numerical fluid mechanics and multidisciplinary design. Vol. 109
Y1  - 2010
SN  - 978-3-642-04087-0
SP  - 205
EP  - 238
PB  - Springer
CY  - Berlin
ER  - 
TY  - CHAP
A1  - Reimer, Lars
A1  - Braun, Carsten
A1  - Chen, B.-H.
A1  - Ballmann, Josef
T1  - Computational aeroelastic analysis and design of the HIRENASD wind tunnel wing model and tests
T2  - Proceedings / IFASD 2007, CEAS/AIAA/KTH International Forum on Aeroelasticity and Structural Dynamics : June 18 - 21, 2007, Stockholm, Sweden
Y1  - 2007
PB  - KTH
CY  - Stockholm
ER  - 
TY  - CHAP
A1  - Reimer, Lars
A1  - Braun, Carsten
A1  - Ballmann, Josef
T1  - Computational study of the aeroelastic equilibrium configuration of a swept wind tunnel wing model in subsonic flow
T2  - High performance computing in science and engineering '06. Transactions of the High Performance Computing Center Stuttgart (HLRS) 2006 /  Wolfgang E. Nagel ... Eds.
N2  - In the Collaborative Research Center SFB 401 at RWTH Aachen University, the numerical aeroelastic method SOFIA for direct numerical aeroelastic simulation is being progressively developed. Numerical results obtained by applying SOFIA were compared with measured data of static and dynamic aeroelastic wind tunnel tests for an elastic swept wing in subsonic flow.
Y1  - 2007
SN  - 978-3-540-36165-7
SP  - 421
EP  - 434
PB  - Springer
CY  - Berlin [u.a.]
ER  - 
TY  - CHAP
A1  - Reimer, Lars
A1  - Braun, Carsten
A1  - Ballmann, Josef
T1  - Analysis of the static and dynamic aero-structural response of an elastic swept wing model by direct aeroelastic simulation
T2  - ICAS 2006 proceedings : 25th Congress of the International Council of the Aeronautical Sciences ; Hamburg, Germany, 3 - 8 September, 2006 : 25th International Congress of Aeronautical Sciences
Y1  - 2006
SN  - 0-9533991-7-6
SP  - Paper No. 2006-10.3.3
PB  - Optimage
CY  - Edinburgh
ER  - 
TY  - JOUR
A1  - Recker, Elmar
A1  - Bosschaerts, Walter
A1  - Wagemakers, Rolf
A1  - Hendrick, Patrick
A1  - Funke, Harald
A1  - Börner, Sebastian
T1  - Experimental study of a round jet in cross-flow at low momentum ratio
JF  - 15th International Symposium on Applications of Laser Techniques to Fluid Mechanics Lisbon, Portugal, 05-08 July, 2010 - 1
Y1  - 2010
SP  - 1
EP  - 13
ER  - 
TY  - CHAP
A1  - Quitter, Julius
A1  - Marino, Matthew
A1  - Bauschat, J.-Michael
T1  - Highly Non-Planar Aircraft Configurations: Estimation of Flight Mechanical Derivatives Using Low-Order Methods
T2  - Deutscher Luft- und Raumfahrtkongress 2019, DLRK 2019. Darmstadt, Germany
Y1  - 2019
ER  - 
TY  - CHAP
A1  - Plescher, Engelbert
A1  - Mathiak, Gerhard
A1  - Willnecker, Rainer
T1  - Technical aspects of liquid diffusion model experiments
T2  - 55th International Astronautical Congress : October 4 - 8, 2004, Vancouver, Canada / International Astronautical Federation. Bd. 8. IAC-04-J.5.04
Y1  - 2005
SP  - 5019
EP  - 5025
PB  - International Astronautical Federation
CY  - Paris
ER  - 
TY  - CHAP
A1  - Pirovano, Laura
A1  - Seefeldt, Patric
A1  - Dachwald, Bernd
A1  - Noomen, Ron
T1  - Attitude and Orbital Dynamics Modeling for an Uncontrolled Solar-Sail Experiment in Low-Earth Orbit
T2  - 25th International Symposium on Spaceflight Dynamics, 2015, Munich, Germany
Y1  - 2015
ER  - 
TY  - CHAP
A1  - Pirovano, Laura
A1  - Seefeldt, Patric
A1  - Dachwald, Bernd
A1  - Noomen, Ron
T1  - Attitude and orbital modeling of an uncontrolled solar-sail experiment in low-Earth orbit
T2  - 25th International Symposium on Space Flight Dynamics ISSFD
N2  - Gossamer-1 is the first project of the three-step Gossamer roadmap, the purpose of which is to develop, prove and demonstrate that solar-sail technology is a safe and reliable propulsion technique for long-lasting and high-energy missions. This paper firstly presents the structural analysis performed on the sail to understand its elastic behavior. The results are then used in attitude and orbital simulations. The model considers the main forces and torques that a satellite experiences in low-Earth orbit coupled with the sail deformation. Doing the simulations for varying initial conditions in attitude and rotation rate, the results show initial states to avoid and maximum rotation rates reached for correct and faulty deployment of the sail. Lastly comparisons with the classic flat sail model are carried out to test the hypothesis that the elastic behavior does play a role in the attitude and orbital behavior of the sail
KW  - Solar sail
KW  - Gossamer structures
KW  - Attitude dynamics
KW  - Orbital dynamics
Y1  - 2015
N1  - 25th International Symposium on Space Flight Dynamics ISSFD
October 19 – 23, 2015, Munich, Germany
https://issfd.org/2015/
SP  - 1
EP  - 15
ER  - 
TY  - JOUR
A1  - Pichler, A.
A1  - George, A.
A1  - Seiler, F.
A1  - Srulijes, J.
A1  - Havermann, Marc
T1  - Doppler Picture Velocimetry (DPV) applied to hypersonics
JF  - Shock Waves [Elektronische Ressource] : 26th International Symposium on Shock Waves, Volume 1 / edited by Klaus Hannemann, Friedrich Seiler
Y1  - 2009
SN  - 978-3-540-85168-4
N1  - International Symposium on Shock Waves ; (26 ; 2007.07.15-20 ; Göttingen) ; ISSW ; (26 ; 2007.07.15-20 ; Göttingen)
SP  - 503
EP  - 508
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Peloni, Alessandro
A1  - Dachwald, Bernd
A1  - Ceriotti, Matteo
T1  - Multiple near-earth asteroid rendezvous mission: Solar-sailing options
JF  - Advances in Space Research
Y1  - 2017
U6  - https://doi.org/10.1016/j.asr.2017.10.017
SN  - 0273-1177
IS  - In Press, Corrected Proof
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - CHAP
A1  - Peloni, Alessandro
A1  - Dachwald, Bernd
A1  - Ceriotti, Matteo
T1  - Multiple NEA rendezvous mission: Solar sailing options
T2  - Fourth International Symposium on Solar Sailing
N2  - The scientific interest in near-Earth asteroids (NEAs) and the classification of some of those as potentially hazardous asteroid for the Earth stipulated the interest in NEA exploration. Close-up observations of these objects will increase drastically our knowledge about the overall NEA population. For this reason, a multiple NEA rendezvous mission through solar sailing is investigated, taking advantage of the propellantless nature of this groundbreaking propulsion technology. Considering a spacecraft based on the DLR/ESA Gossamer technology, this work focuses on the search of possible sequences of NEA encounters. The effectiveness of this approach is demonstrated through a number of fully-optimized trajectories. The results show that it is possible to visit five NEAs within 10 years with near-term solar-sail technology. Moreover, a study on a reduced NEA database demonstrates the reliability of the approach used, showing that 58% of the sequences found with an approximated trajectory model can be converted into real solar-sail trajectories. Lastly, this second study shows the effectiveness of the proposed automatic optimization algorithm, which is able to find solutions for a large number of mission scenarios without any input required from the user.
KW  - Multiphase
KW  - Trajectory Optimization
KW  - Automated Optimization
KW  - Gossamer
KW  - Sequence-Search
Y1  - 2017
N1  - Fourth International Symposium on Solar Sailing (ISSS 2017), Kyoto, Japan, 17-20 Jan 2017.
http://www.jsforum.or.jp/ISSS2017/
SP  - 1
EP  - 11
ER  - 
TY  - JOUR
A1  - Peloni, Alessandro
A1  - Ceriotti, Matteo
A1  - Dachwald, Bernd
T1  - Solar-sail trajectory design for a multiple near-earth-asteroid rendezvous mission
JF  - Journal of Guidance, Control, and Dynamics
N2  - The scientific interest for near-Earth asteroids as well as the interest in potentially hazardous asteroids from the perspective of planetary defense led the space community to focus on near-Earth asteroid mission studies. A multiple near-Earth asteroid rendezvous mission with close-up observations of several objects can help to improve the characterization of these asteroids. This work explores the design of a solar-sail spacecraft for such a mission, focusing on the search of possible sequences of encounters and the trajectory optimization. This is done in two sequential steps: a sequence search by means of a simplified trajectory model and a set of heuristic rules based on astrodynamics, and a subsequent optimization phase. A shape-based approach for solar sailing has been developed and is used for the first phase. The effectiveness of the proposed approach is demonstrated through a fully optimized multiple near-Earth asteroid rendezvous mission. The results show that it is possible to visit five near-Earth asteroids within 10 years with near-term solar-sail technology.
Y1  - 2016
U6  - https://doi.org/10.2514/1.G000470
SN  - 0731-5090
VL  - 39
IS  - 12
SP  - 2712
EP  - 2724
PB  - AIAA
CY  - Reston, Va.
ER  - 
TY  - CHAP
A1  - Peloni, A.
A1  - Ceriotti, M.
A1  - Dachwald, Bernd
T1  - Preliminary trajectory design of a multiple NEO rendezvous mission through solar sailing
T2  - Proceedings of the International Astronautical Congress, IAC, Vol. 8, 2014
Y1  - 2015
SN  - 978-1-63439-986-9
SP  - 5352
EP  - 5366
PB  - Curran
CY  - Red Hook, NY
ER  - 
TY  - CHAP
A1  - Peeken, Heinz
A1  - Troeder, Christoph
A1  - Schmidt, J.
A1  - Rosenkranz, Josef
T1  - Principles of machine noise reduction
T2  - Inter-noise 85 : proceedings ; 1985 international conference on noise control engineering ; Munich, Sept. 18 - 20, 1985. - (Schriftenreihe der Bundesanstalt für Arbeitsschutz : Tagungsbericht ; 39)
Y1  - 1985
SN  - 3-88314-417-7
SP  - 23
EP  - 36
PB  - Bundesanstalt für Arbeitsschutz [u.a.]
CY  - Dortmund [u.a.]
ER  - 
TY  - JOUR
A1  - Overduin, James
A1  - Blome, Hans-Joachim
A1  - Hoell, Josef
T1  - Wolfgang Priester: from the big bounce to the Lambda-dominated universe
JF  - Naturwissenschaften
Y1  - 2007
SN  - 0028-1042
VL  - 94
IS  - 6
SP  - 417
EP  - 429
ER  - 
TY  - JOUR
A1  - Otten, Dennis
A1  - Weber, Tobias
A1  - Arent, Jan-Christoph
T1  - Manufacturing Process Simulation – On Its Way to Industrial Application
JF  - International Journal of Aviation, Aeronautics, and Aerospace
N2  - Manufacturing process simulation (MPS) has become more and more important for aviation and the automobile industry. A highly competitive market requires the use of high performance metals and composite materials in combination with reduced manufacturing cost and time as well as a minimization of the time to market for a new product. However, the use of such materials is expensive and requires sophisticated manufacturing processes. An experience based process and tooling design followed by a lengthy trial-and-error optimization is just not contemporary anymore. Instead, a tooling design process aided by simulation is used more often. This paper provides an overview of the capabilities of MPS in the fields of sheet metal forming and prepreg autoclave manufacturing of composite parts summarizing the resulting benefits for tooling design and manufacturing engineering. The simulation technology is explained briefly in order to show several simplification and optimization techniques for developing industrialized simulation approaches. Small case studies provide examples of an efficient application on an industrial scale.
Y1  - 2018
U6  - https://doi.org/10.15394/ijaaa.2018.1217
SN  - 2374-6793
VL  - 5
IS  - 2
PB  - Embry-Riddle Aeronautical University
CY  - Daytona Beach, Fla.
ER  - 
TY  - CHAP
A1  - Otten, D.
A1  - Schmidt, M.
A1  - Weber, Tobias
T1  - Advances in Determination of Material Parameters for Functional Simulations Based on Process Simulations
T2  - SAMPE Europe Conference 16 Liege
Y1  - 2016
SN  - 978-1-5108-3800-0
SP  - 570
EP  - 577
ER  - 
TY  - CHAP
A1  - Otten, D.
A1  - Schmid, M.
A1  - Weber, Tobias
T1  - Advances In Sheet Metal-Forming: Reduction Of Tooling Cost By Methodical Optimization
T2  - Proceedings of SAMPE Europe Conference, Amiens , France
Y1  - 2015
ER  - 
TY  - JOUR
A1  - Olaru, Alexandra Maria
A1  - Kowalski, Julia
A1  - Sethi, Vaishali
A1  - Blümich, Bernhard
T1  - Exchange relaxometry of flow at small Péclet numbers in a glass bead pack
JF  - Journal of Magnetic Resonance (JMR)
N2  - In this paper we consider low Péclet number flow in bead packs. A series of relaxation exchange experiments has been conducted and evaluated by ILT analysis. In the resulting correlation maps, we observed a collapse of the signal and a translation towards smaller relaxation times with increasing flow rates, as well as a signal tilt with respect to the diagonal. In the discussion of the phenomena we present a mathematical theory for relaxation exchange experiments that considers both diffusive and advective transport. We perform simulations based on this theory and discuss them with respect to the conducted experiments.
KW  - NMR exchange relaxometry
KW  - Low-field NMR
Y1  - 2012
U6  - https://doi.org/10.1016/j.jmr.2012.04.015
SN  - 1096-0856
VL  - 220
SP  - 32
EP  - 44
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - CHAP
A1  - Olaru, Alexandra Maria
A1  - Kowalski, Julia
A1  - Sethi, Vaishali
A1  - Blümich, Bernhard
T1  - Fluid Transport in Porous Media probed by Relaxation-Exchange NMR
T2  - 2011 Fall Meeting, AGU, San Francisco, Calif., 5-9 Dec.
Y1  - 2011
N1  - H12B-07; American Geophysical Union
ER  - 
TY  - CHAP
A1  - Ohndorf, Andreas
A1  - Dachwald, Bernd
A1  - Seboldt, Wolfgang
A1  - Schartner, Karl-Heinz
T1  - Flight times to the heliopause using a combination of solar and radioisotope electric propulsion
T2  - 32nd International Electric Propulsion Conference
N2  - We investigate the interplanetary flight of a low-thrust space probe to the heliopause,located at a distance of about 200 AU from the Sun. Our goal was to reach this distance within the 25 years postulated by ESA for such a mission (which is less ambitious than the 15-year goal set by NASA). Contrary to solar sail concepts and combinations of allistic and electrically propelled flight legs, we have investigated whether the set flight time limit could also be kept with a combination of solar-electric propulsion and a second, RTG-powered upper stage. The used ion engine type was the RIT-22 for the first stage and the RIT-10 for the second stage. Trajectory optimization was carried out with the low-thrust optimization program InTrance, which implements the method of Evolutionary Neurocontrol,using Artificial Neural Networks for spacecraft steering and Evolutionary Algorithms to optimize the Neural Networks’ parameter set. Based on a parameter space study, in which the number of thrust units, the unit’s specific impulse, and the relative size of the solar power generator were varied, we have chosen one configuration as reference. The transfer time of this reference configuration was 29.6 years and the fastest one, which is technically
more challenging, still required 28.3 years. As all flight times of this parameter study were longer than 25 years, we further shortened the transfer time by applying a launcher-provided hyperbolic excess energy up to 49 km2/s2. The resulting minimal flight time for the reference configuration was then 27.8 years. The following, more precise optimization to a launch with the European Ariane 5 ECA rocket reduced the transfer time to 27.5 years. This is the fastest mission design of our study that is flexible enough to allow a launch every
year. The inclusion of a fly-by at Jupiter finally resulted in a flight time of 23.8 years,which is below the set transfer-time limit. However, compared to the 27.5-year transfer,this mission design has a significantly reduced launch window and mission flexibility if the
escape direction is restricted to the heliosphere’s “nose".
KW  - low-thrust trajectory optimization
KW  - heliosphere
KW  - ion propulsion
Y1  - 2011
N1  - IEPC-2011-051
32nd International Electric Propulsion Conference,September 11–15, 2011
Wiesbaden, Germany
SP  - 1
EP  - 12
ER  - 
TY  - CHAP
A1  - Nowack, N.
A1  - Röth, Thilo
A1  - Bührig-Polaczek, A.
A1  - Klaus, G.
ED  - Hirsch, Jürgen
T1  - Advanced Sheet Metal Components Reinforced by Light Metal Cast Structures
T2  - Aluminium alloys : their physical and mechanical properties ; [proceedings of the 11th International Conference on Aluminium Alloys, 22 - 26 Sept. 2008, Aachen, Germany ; ICAA 11]
Y1  - 2008
SN  - 978-3-527-32367-8
IS  - 2
SP  - 2374
EP  - 2381
ER  - 
TY  - CHAP
A1  - Niedermeier, H.
A1  - Clemens, J.
A1  - Kowalski, Julia
A1  - Macht, S.
A1  - Heinen, D.
A1  - Hoffmann, R.
A1  - Linder, Peter
T1  - Navigation system for a research ice probe for antarctic glaciers
T2  - IEEE/ION Position, Location and Navigation Symposium (PLANS) ; 5-8 May 2014, Monterey, Calif.
Y1  - 2014
SN  - 978-1-4799-3319-8
SP  - 959
EP  - 975
PB  - IEEE
CY  - Piscataway, NJ
ER  - 
TY  - CHAP
A1  - Neu, Eugen
A1  - Janser, Frank
A1  - Khatibi, Akbar A.
A1  - Orifici, Adrian C.
T1  - Operational modal analysis of a cantilever in a wind tunnel using optical fiber bragg grating sensors
T2  - 6th International Operational Modal Analysis Conference. IOMAC´15. 2015 May 12-14 Gijon - Spain
Y1  - 2015
U6  - https://doi.org/10.13140/RG.2.1.3753.0324
ER  - 
TY  - CHAP
A1  - Neu, Eugen
A1  - Janser, Frank
A1  - Khatibi, Akbar A.
A1  - Orifici, Adrian C.
T1  - In-flight vibration-based structural health monitoring of aircraft wings
T2  - 30th Congress of the internatonal council of the aeronautical sciences : 25.-30. September 2016, Daejeon, Korea
N2  - This work presents a methodology for automated
damage-sensitive feature extraction and anomaly
detection under multivariate operational variability
for in-flight assessment of wings. The
method uses a passive excitation approach, i. e.
without the need for artificial actuation. The
modal system properties (natural frequencies and
damping ratios) are used as damage-sensitive
features. Special emphasis is placed on the use
of Fiber Bragg Grating (FBG) sensing technology
and the consideration of Operational and
Environmental Variability (OEV). Measurements
from a wind tunnel investigation with a composite
cantilever equipped with FBG and piezoelectric
sensors are used to successfully detect an impact
damage. In addition, the feasibility of damage
localisation and severity estimation is evaluated
based on the coupling found between damageand
OEV-induced feature changes.
Y1  - 2016
ER  - 
TY  - JOUR
A1  - Neu, Eugen
A1  - Janser, Frank
A1  - Khatibi, Akbar A.
A1  - Orifici, Adrian C.
T1  - Fully Automated Operational Modal Analysis using multi-stage clustering
JF  - Mechanical Systems and Signal Processing
Y1  - 2017
U6  - https://doi.org/10.1016/j.ymssp.2016.07.031
SN  - 0888-3270
VL  - Vol. 84, Part A
SP  - 308
EP  - 323
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Neu, Eugen
A1  - Janser, Frank
A1  - Khatibi, Akbar A.
A1  - Orifici, Adrian C.
T1  - Automated modal parameter-based anomaly detection under varying wind excitation
JF  - Structural Health Monitoring
N2  - Wind-induced operational variability is one of the major challenges for structural health monitoring of slender engineering structures like aircraft wings or wind turbine blades. Damage sensitive features often show an even bigger sensitivity to operational variability. In this study a composite cantilever was subjected to multiple mass configurations, velocities and angles of attack in a controlled wind tunnel environment. A small-scale impact damage was introduced to the specimen and the structural response measurements were repeated. The proposed damage detection methodology is based on automated operational modal analysis. A novel baseline preparation procedure is described that reduces the amount of user interaction to the provision of a single consistency threshold. The procedure starts with an indeterminate number of operational modal analysis identifications from a large number of datasets and returns a complete baseline matrix of natural frequencies and damping ratios that is suitable for subsequent anomaly detection. Mahalanobis distance-based anomaly detection is then applied to successfully detect the damage under varying severities of operational variability and with various degrees of knowledge about the present operational conditions. The damage detection capabilities of the proposed methodology were found to be excellent under varying velocities and angles of attack. Damage detection was less successful under joint mass and wind variability but could be significantly improved through the provision of the currently encountered operational conditions.
Y1  - 2016
U6  - https://doi.org/10.1177/1475921716665803
SN  - 1475-9217
VL  - 15
IS  - 6
SP  - 1
EP  - 20
PB  - Sage
CY  - London
ER  - 
TY  - JOUR
A1  - Neu, Eugen
A1  - Janser, Frank
A1  - Khatibi, Akbar A.
A1  - Braun, Carsten
A1  - Orifici, Adrian C.
T1  - Operational Modal Analysis of a wing excited by transonic flow
JF  - Aerospace Science and Technology
N2  - Operational Modal Analysis (OMA) is a promising candidate for flutter testing and Structural Health Monitoring (SHM) of aircraft wings that are passively excited by wind loads. However, no studies have been published where OMA is tested in transonic flows, which is the dominant condition for large civil aircraft and is characterized by complex and unique aerodynamic phenomena. We use data from the HIRENASD large-scale wind tunnel experiment to automatically extract modal parameters from an ambiently excited wing operated in the transonic regime using two OMA methods: Stochastic Subspace Identification (SSI) and Frequency Domain Decomposition (FDD). The system response is evaluated based on accelerometer measurements. The excitation is investigated from surface pressure measurements. The forcing function is shown to be non-white, non-stationary and contaminated by narrow-banded transonic disturbances. All these properties violate fundamental OMA assumptions about the forcing function. Despite this, all physical modes in the investigated frequency range were successfully identified, and in addition transonic pressure waves were identified as physical modes as well. The SSI method showed superior identification capabilities for the investigated case. The investigation shows that complex transonic flows can interfere with OMA. This can make existing approaches for modal tracking unsuitable for their application to aircraft wings operated in the transonic flight regime. Approaches to separate the true physical modes from the transonic disturbances are discussed.
Y1  - 2016
U6  - https://doi.org/10.1016/j.ast.2015.11.032
SN  - 1270-9638
VL  - 49
SP  - 73
EP  - 79
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Möhren, Felix
A1  - Bergmann, Ole
A1  - Janser, Frank
A1  - Braun, Carsten
T1  - On the influence of elasticity on propeller performance: a parametric study
JF  - CEAS Aeronautical Journal
N2  - The aerodynamic performance of propellers strongly depends on their geometry and, consequently, on aeroelastic deformations. Knowledge of the extent of the impact is crucial for overall aircraft performance. An integrated simulation environment for steady aeroelastic propeller simulations is presented. The simulation environment is applied to determine the impact of elastic deformations on the aerodynamic propeller performance. The aerodynamic module includes a blade element momentum approach to calculate aerodynamic loads. The structural module is based on finite beam elements, according to Timoshenko theory, including moderate deflections. Several fixed-pitch propellers with thin-walled cross sections made of both isotropic and non-isotropic materials are investigated. The essential parameters are varied: diameter, disc loading, sweep, material, rotational, and flight velocity. The relative change of thrust between rigid and elastic blades quantifies the impact of propeller elasticity. Swept propellers of large diameters or low disc loadings can decrease the thrust significantly. High flight velocities and low material stiffness amplify this tendency. Performance calculations without consideration of propeller elasticity can lead to decreased efficiency. To avoid cost- and time-intense redesigns, propeller elasticity should be considered for swept planforms and low disc loadings.
KW  - Propeller
KW  - Finite element method
KW  - Blade element method
KW  - Propeller elasticity
KW  - Aeroelasticity
Y1  - 2023
U6  - https://doi.org/10.1007/s13272-023-00649-y
SN  - 1869-5590 (Online)
SN  - 1869-5582 (Print)
N1  - Corresponding author: Felix Möhren
VL  - 14
SP  - 311
EP  - 323
PB  - Springer Nature
CY  - Berlin
ER  - 
TY  - CHAP
A1  - Möhren, Felix
A1  - Bergmann, Ole
A1  - Janser, Frank
A1  - Braun, Carsten
T1  - On the determination of harmonic propeller loads
T2  - AIAA SCITECH 2023 Forum
N2  - Dynamic loads significantly impact the structural design of propeller blades due to fatigue and static strength. Since propellers are elastic structures, deformations and aerodynamic loads are coupled. In the past, propeller manufacturers established procedures to determine unsteady aerodynamic loads and the structural response with analytical steady-state calculations. According to the approach, aeroelastic coupling primarily consists of torsional deformations. They neglect bending deformations, deformation velocities, and inertia terms. This paper validates the assumptions above for a General Aviation propeller and a lift propeller for urban air mobility or large cargo drones. Fully coupled reduced-order simulations determine the dynamic loads in the time domain. A quasi-steady blade element momentum approach transfers loads to one-dimensional finite beam elements. The simulation results are in relatively good agreement with the analytical method for the General Aviation propeller but show increasing errors for the slender lift propeller. The analytical approach is modified to consider the induced velocities. Still, inertia and velocity proportional terms play a significant role for the lift propeller due to increased elasticity. The assumption that only torsional deformations significantly impact the dynamic loads of propellers is not valid. Adequate determination of dynamic loads of such designs requires coupled aeroelastic simulations or advanced analytical procedures.
Y1  - 2023
U6  - https://doi.org/10.2514/6.2023-2404
N1  - AIAA SCITECH 2023 Forum, 23-27 January 2023, National Harbor, Md & Online
PB  - AIAA
ER  - 
TY  - JOUR
A1  - Möhren, Felix
A1  - Bergmann, Ole
A1  - Janser, Frank
A1  - Braun, Carsten
T1  - Assessment of structural mechanical effects related to torsional deformations of propellers
JF  - CEAS Aeronautical Journal
N2  - Lifting propellers are of increasing interest for Advanced Air Mobility. All propellers and rotors are initially twisted beams, showing significant extension–twist coupling and centrifugal twisting. Torsional deformations severely impact aerodynamic performance. This paper presents a novel approach to assess different reasons for torsional deformations. A reduced-order model runs large parameter sweeps with algebraic formulations and numerical solution procedures. Generic beams represent three different propeller types for General Aviation, Commercial Aviation, and Advanced Air Mobility. Simulations include solid and hollow cross-sections made of aluminum, steel, and carbon fiber-reinforced polymer. The investigation shows that centrifugal twisting moments depend on both the elastic and initial twist. The determination of the centrifugal twisting moment solely based on the initial twist suffers from errors exceeding 5% in some cases. The nonlinear parts of the torsional rigidity do not significantly impact the overall torsional rigidity for the investigated propeller types. The extension–twist coupling related to the initial and elastic twist in combination with tension forces significantly impacts the net cross-sectional torsional loads. While the increase in torsional stiffness due to initial twist contributes to the overall stiffness for General and Commercial Aviation propellers, its contribution to the lift propeller’s stiffness is limited. The paper closes with the presentation of approximations for each effect identified as significant. Numerical evaluations are necessary to determine each effect for inhomogeneous cross-sections made of anisotropic material.
KW  - Lifting propeller
KW  - Extension–twist coupling
KW  - Trapeze effect
KW  - Centrifugal twisting moment
Y1  - 2024
U6  - https://doi.org/10.1007/s13272-024-00737-7
SN  - 1869-5590 (eISSN)
SN  - 1869-5582
N1  - Corresponding author: Felix Möhren
PB  - Springer
CY  - Wien
ER  - 
TY  - CHAP
A1  - Mulsow, Niklas A.
A1  - Hülsen, Benjamin
A1  - Gützlaff, Joel
A1  - Spies, Leon
A1  - Bresser, Andreas
A1  - Dabrowski, Adam
A1  - Czupalla, Markus
A1  - Kirchner, Frank
T1  - Concept and design of an autonomous micro rover for long term lunar exploration
T2  - Proceedings of the 74th International Astronautical Congress
N2  - Research on robotic lunar exploration has seen a broad revival, especially since the Google Lunar X-Prize increasingly brought private endeavors into play. This development is supported by national agencies with the aim of enabling long-term lunar infrastructure for in-situ operations and the establishment of a moon village. One challenge for effective exploration missions is developing a compact and lightweight robotic rover to reduce launch costs and open the possibility for secondary payload options. Existing micro rovers for exploration missions are clearly limited by their design for one day of sunlight and their low level of autonomy. For expanding the potential mission applications and range of use, an extension of lifetime could be reached by surviving the lunar night and providing a higher level of autonomy. To address this objective, the paper presents a system design concept for a lightweight micro rover with long-term mission duration capabilities, derived from a multi-day lunar mission scenario at equatorial regions. Technical solution approaches are described, analyzed, and evaluated, with emphasis put on the harmonization of hardware selection due to a strictly limited budget in dimensions and power.
Y1  - 2023
N1  - 74. International Astronautical Congress (IAC-2023), October 2-6 2023, Baku, Azerbaijan
PB  - dfki
CY  - Saarbrücken
ER  - 
TY  - JOUR
A1  - Meyer, Max-Arno
A1  - Granrath, Christian
A1  - Feyerl, Günter
A1  - Richenhagen, Johannes
A1  - Kaths, Jakob
A1  - Andert, Jakob
T1  - Closed-loop platoon simulation with cooperative intelligent transportation systems based on vehicle-to-X communication
JF  - Simulation Modelling Practice and Theory
Y1  - 2021
U6  - https://doi.org/10.1016/j.simpat.2020.102173
SN  - 1569-190X
VL  - 106
IS  - Art. 102173
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - BOOK
A1  - Mertens, Josef
A1  - Velden, Alexander van der
A1  - Kelm, Roland
A1  - Kokan, David
T1  - Application of MDO to large subsonic transport aircraft
Y1  - 2000
N1  - Aerospace Sciences Meeting and Exhibit <38, 2000, Reno, NV> ; (AIAA Paper ; 00-0844)
PB  - American Institute of Aeronautics and Astronautics
CY  - Reston, Va.
ER  - 
TY  - PAT
A1  - Mertens, Josef
A1  - Lajain, Henri
T1  - Method of fabricating leading edge nose structures of aerodynamic surfaces : patent no.: US 6,415,510 B2 ; date of patent: Jul. 9, 2002
Y1  - 2002
N1  - Volltext auch in der Datenbank http://publikationen.dpma.de/ zu finden unter der Nummer US000006415510B2
PB  - United States Patent and Trademark Office
CY  - [Washington, DC]
ER  - 
TY  - JOUR
A1  - Mertens, Josef
A1  - Klevenhusen, K. D.
A1  - Jakob, H.
T1  - Accurate Transonic Wave Drag Prediction Using Simple Physical Models
JF  - AIAA-Journal. 25 (1987), H. 6
Y1  - 1987
SN  - 0001-1452
SP  - 799
EP  - 805
ER  - 
TY  - JOUR
A1  - Mertens, Josef
A1  - Henke, Rolf
T1  - Adaptive technologies for future civil air transport
JF  - Air & Space Europe. 3 (2001), H. 3-4
Y1  - 2001
SN  - 1247-5793
SP  - 80
EP  - 82
ER  - 
TY  - CHAP
A1  - Mertens, Josef
A1  - Becker, K.
ED  - Ballmann, Josef
T1  - Numerical solution of flow equations : an aircraft designer's view
T2  - Nonlinear hyperbolic equations - theory, computation methods, and applications : proceedings of the 2nd International Conference on Nonlinear Hyperbolic Problems, Aachen, FRG, March 14 to 18, 1988. - (Notes on Numerical Fluid Mechanics ; 24)
N2  - Today the most accurate and cost effective industrial codes used in aircraft design are based on the full potential equation coupled with boundary layer equations. However, these are not capable to solve complicated three-dimensional problems of vortical flows and shocks. On the other hand Euler and Navier-Stokes codes are too expensive and not accurate enough for design purposes, especially in regard of drag and interference prediction. The reasons for these deficiencies are investigated and a way to overcome them by future developments is demonstrated.
Y1  - 1989
SN  - 3-528-08098-1
U6  - https://doi.org/10.1007/978-3-322-87869-4_41
N1  - International Conference on Nonlinear Hyperbolic Problems <3, 1988, Aachen>
SP  - 403
EP  - 412
PB  - Vieweg
CY  - Braunschweig
ER  - 
TY  - CHAP
A1  - Mertens, Josef
T1  - Laminar leading edges: manufacturing, contamination, and operational aspects - results from the German RaWid programme
N2  - RaWid was the German national technology programme on transonic aerodynamics and supporting technologies, lasting from 1995 to 1998. One of the main topics was laminar wing development. Besides aerodynamic design work, many operational aspects were investigated. A manufacturing concept was developed to be applied to operational laminar wings and empennages. It was built in a large scale manufacturing demonstrator with the aerodynamic shape of a 1,5 m section of the A320 fin nose. Tolerances in shape and roughness fulfilled all requirements. The construction can easily be adapted to varying stiffness and strength requirements. Weight and manufacturing costs are comparable to common nose designs. The mock-up to be designed in ALTTA is based on this manufacturing principle. Another critical point is contamination of suction surfaces. Several tests were performed to investigate perforated titanium suction surfaces at realistic operational conditions: - a one year flight test with a suction plate in the stagnation area of the Airbus "Beluga" - a one year test of several suction plates in a ground test near the airport - a one year test of a working suction ground test installation at all weather conditions. No critical results were found. There is no long term suction degradation visible. Icing conditions and ground de-icing fluids used on airports did not pose severe problems. Some problems detected require only respection of weak design constraints.
KW  - Laminare Strömung
KW  - Ansaugsystem
KW  - Profilumströmung
KW  - Laminarprofil
KW  - RaWid
KW  - hybrid laminar flow
KW  - suction systems
KW  - suction structure
KW  - contamination
KW  - operational aspects
Y1  - 2000
ER  -